Make ObjectItem default as "Card"
Summary: This went smoother than expeced. Makes the rounded Card the default, also tweaked selected state a little.
Test Plan:
Test UIExamples, Maniphest, Home, Differential, Harbormaster, Audit. Everything seems normal
Reviewers: epriestley
Reviewed By: epriestley
Subscribers: epriestley, Korvin
Differential Revision: https://secure.phabricator.com/D9408